1. Field of the Invention
The present invention relates to biosoluble inorganic fiber and a method for manufacturing same.
2. Description of the Related Art
Inorganic fibers such as heat-resistant glass wools and ceramic fibers are widely used for the purpose of heat insulation in various types of building structures due to their excellent heat-resistance properties.
In recent years, however, the potential for bodily harm from the inhalation of inorganic fibers has become a serious concern of the general public. Comparatively large inorganic fibers do not have much effect on human health as they are trapped in nose or mouth, while fine inorganic fibers may pass through the nostrils or oral cavity, enter the lungs and cause inflammation of lung cells, by which mutation of DNA genes or the growth of cancer cells can be induced. Thus, there is a need for a countermeasure against this health problem.
Imparting inorganic fibers with the property of bio-solubility (dissolvable in the living body) is known to be an effective countermeasure for the problem. Japanese Patent No. 3630167 discloses one example of such a bio-soluble inorganic fiber.
However, there is a challenge to overcome in the use of the bio-soluble inorganic fiber. Bio-soluble inorganic fibers are often processed into blankets, mats or felt materials for use as heat insulation in buildings structures. Once woven into these products, they do not demonstrate sufficient tensile strength per single fiber, affecting the general strength of the products.